The FDA action comes nearly six years after the drug was banned in the U.K., and nearly a year and a half after the European drug agency banned it.

The public interest group Public Citizen petitioned the FDA to ban the drug in 1978 and again in 2006. The latter petition caused the FDA to take the matter to an expert advisory committee, which in July 2009 voted 14-12 to ban the drug.

But the FDA overruled the panel, instead asking Darvon/Darvocet maker Xanodyne Pharmaceuticals Inc. to conduct studies of the drug's effects on the heart. The results of those studies led to the FDA ban.

"The drug puts patients at risk of abnormal or even fatal heart rhythm abnormalities," John Jenkins, MD, director of the FDA's office of new drugs at the Center for Drug Evaluation and Research, said at a news conference. "Combined with prior safety data, this altered our risk assessment."

The FDA ban comes too late for Public Citizen, which blasted the FDA for waiting far too long to protect the public.

"Due to FDA negligence, at least 1,000 to 2,000 or more people in the U.S. have died from using propoxyphene since the time the U.K. ban was announced," Sidney Wolfe, director of Public Citizen's health research group, says in a news release.

Wolfe says Public Citizen will call for a congressional investigation into who at the FDA "was responsible for the loss of so many lives in this country."